Centrifugal fuse



H. JUNGHANS Sept. 2o, 1938.

CENTRIFUGAL FUSE Filed Jan. 7. 1955 1 f @e .a

w f /w Patented sept. 2o,` 193s UNITED STATES CEN'I'BJFUGAI.A FUSE H elmut Junghan, Srieramberg-Snlgen, Ecken- Application JanuaryA 7, 1936, Serial No. 57,992

In Germany January 18, 1935 4 claims. (Cl. 1oz- 39) 'Ihe invention relates to detonators with centrifugal jaw arrangement for securing the ignition pin and has for its object to provide special means for securing the centrifugal jaws.

5 According to the invention, the centrifugal jaws are locked in the rest position owing to the fact that the ignition pin holds them together by means of a locking arrangement.

In a suitable form of construction according to l the inventidn the locking arrangement consists of a projection arranged von the ignition pin,

which is formed of an annularV recess in the igni tion pin and in the safety position engages with projections of the centrifugal jaws. In order to l facilitate the swinging out of the centrifugal jaws when the centrifugal force is exerted, the surface of the ignition pin recess whichvlies opposite the projections is provided with an inclination.

According to a further feature of the invention,

E0 a locking device is provided which prevents the ignitionpin projection from leaving the centrifugal jaws in the inoperative position ofthe parts.

Moreover, resilient means may be arranged on the centrifugal jaws so that the latter must over- 25 come anrincrease resistance in their movement in the outward direction. l

A constructional example of the invention is illustratedin the accompanying drawing, in which:

Figure l is a longitudinal section of the detonator with the parts in the safety position,

Figure 2 is a plan view of the detonator parts according to Figure 1, the cap being removed,

Figure 3 is a longitudinal section of the det- B5 onator according to Figure l, the ignition pin lying in the position ready for operation, and

Figure 4 is a plan View of the detonator parts according to Figure 3.

, In the axis of the detonator casing formed of l0' the cap a and the base b, is situated theignition pin c adapted to slide in the axial direction. Two Ycentrifugal jaws d and e are arranged in a recess in the base and are adapted to carry out pivotal movements about pins f. While in lthe inoperi5 ative position, these centrifugal jaws lieV under a collar C1 on the ignition pin and thus ensure it against axial movement in the direction of the primer (not shown). In the collar ci of the ignition pin, a recess is produced byan annular i0 flange c2 having a cam surface c3 in which the centrifugal jaws d ande engage. On the upper VVsides of the centrifugaljaws are situated seg- -inents diV and e1 engaging behind the flange of the ignition pin, so that the centrifugal jaws 55 are prevented from swinging out. The collar of the ignition pin therefore carries out a double function: flrst, by the placing of the centrifugal 1 jaws under this collar the ignition pin is prevented from moving into the ring position, and thereupon the collar holds together the centrif- 5 ugal jaws by its special construction according to the invention, so thatthey are locked in the inoperative position of the parts by the weight of the ignition pin. In order further to increase the pressure of the ignition pin, a helical spring s may l be provided for. this purpose, which is mounted about the ignition pin or collar ci.

The arrangement of the centrifugal jaws with respect to one another is such that although the jaws both press against the inner edge of the 1 recess of the ignition pin under the action of centrifugal force, onlyone of the centrifugal jaws d can rock out wheny the ignition pin is lifted,

' whereupon, after the jaw d has reached its terminal position, the centrifugal jaw e commences to move. 'I'his is achieved by a lug ez provided on the jaw e, by which this jaw is locked in the safety position until the centrifugal jaw dl after rocking out completely no longer lies in the path of the lug en and has consequently released the jaw e.

In order to lengthen the period of time in which the centrifugal jaws d and e traverse their path, helical springs g and h mounted against the centrifugal jaws `are provided, the counter-pressure of which must also be overcome by the centrifugal jaws on their rocking movement in the outward direction.

.The safety device according to the invention operates in the following manner:

Owing to the firing, the ignition pin a presses with its annular flange ci` against the groove of the centrifugal jaws d and e under the force of inertia acting during the drive, and holds them together until the acceleration of the projectile 40 upon leaving the barrel ceases. When the projectile is situated outside the barrel, the pressure of the ignition pin is overcome by the centrifugal force which has meanwhile been set up, the centrifugal jaws lifting the ignition pin'until the pro- 45 jections d1, el are released. by pressing against the inclined surface of the ignition pin recess. At rst only the centrifugal jaw d can move outwards, the centrifugal jaw e being locked by the lug en in its movement until the jaw d has completely'traversed its path. Not until then does the centrifugal jaw e swing outwards, whereby the ignition pin is released for the sensitive percussion action.

Having now particularly described and ascertained the nature of my said invention and in` what manner the same is to 'be performed, I deaxially anddownwardly extending ange, centrifugal jaws pivotally mounted and cooperating with said ignition pin and each jaw having an axially and upwardly extending ange, said collar being provided on the pin at the upper side of the jaws and the anges of the jaws in the normal position and in radial extension lie behind the flange of the collar of the ignition pin so that the pin interlocks the jaws in the normal position and must be moved forwardly at first under the influence oi? centrifugal force acting upon the jaws before the jaws can move freely outwardly, rnd

a spring associated with the collar to constantly urge the ignition pin into the centrifugal Jaws.

2. A direct impact percussion fuse according to claim 1, in which a base is provided in which the centrifugal Jaws are pivotally mounted, and in which a spring is provided in the base for each jaw to force said jaws inwardly around their pivot pins.

3. A direct impact percussion fuse according to claim 1, in which each jaw and the collar have cooperating bevelled contacting faces.

4. A direct impact 4percussion fuse according to claim 1, in which one of the jaws is provided with a lug normally interlocking with a portion pin one after the othe Y K 

